1. Field of the Invention
The present invention relates to a vehicle wheel, and more particularly, to a vehicle wheel capable of reducing a rolling resistance of a tire attached to a wheel.
2. Description of the Related Art
Conventionally, it is known that rolling resistance decreases as a temperature of a tire of a vehicle rises. High temperature of the tire improves a gas mileage performance of the vehicle, and a gripping force at a tire tread portion is also improved. JP 2009-73247A discloses a technology of applying a heat-shield/heat-insulation coating having a thickness of 50 to 500 μm on a rim outer circumference surface other than a bead seating portion of the rim outer circumference surface and a rim flange portion thereof to form heat-shield/heat-insulation layer (see, in particular, FIG. 1).
According to the technology disclosed in JP2009-73247A, however, as the heat-shield/heat-insulation coating is applied on the rim outer circumference surface, it is necessary to mask the bead seating portion and the rim flange portion before a heat-insulation paint is applied or to process a vehicle wheel while rotating the vehicle wheel in order to prevent the heat-insulation paint from dripping in a painting/drying process and to obtain a uniform thickness, resulting in poor productivity. Also, because the paint is a liquid, it is difficult to control a layer thickness of such a paint to be uniform to secure quality.